CN102277823B - Vehicle-mounted pavement detection system based on inertia measurement unit and laser range finder - Google Patents
Vehicle-mounted pavement detection system based on inertia measurement unit and laser range finder Download PDFInfo
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Abstract
一种基于惯性测量单元和激光测距仪的车载路面检测系统，由惯性测量单元、GPS模块、PC104计算机、里程仪、激光路面测距仪和数据采集板组成，惯性测量单元和GPS模块用于测量车辆运动信息；激光路面测距仪用于测量车辆到路面的距离；里程仪用于测量车辆的行驶距离，并作为数据采集板的触发信号；数据采集板采集惯性测量单元以及激光测距仪的角速度和加速度信号，发送到PC104计算机；PC104计算机接收信号，依次进行惯性测量单元误差补偿、导航解算和信息融合滤波，最后将导航结果与激光测距仪的信息融合，计算得到路面平整度信息。本发明精度高、集成度高、抗振动、操作简便，用于城市道路及高速公路的路面测量。
A vehicle-mounted road surface detection system based on an inertial measurement unit and a laser range finder, which is composed of an inertial measurement unit, a GPS module, a PC104 computer, an odometer, a laser road surface range finder and a data acquisition board, and the inertial measurement unit and the GPS module are used for Measure vehicle motion information; laser road surface rangefinder is used to measure the distance from the vehicle to the road; the odometer is used to measure the driving distance of the vehicle, and as a trigger signal for the data acquisition board; The angular velocity and acceleration signals are sent to the PC104 computer; the PC104 computer receives the signals, performs inertial measurement unit error compensation, navigation calculation and information fusion filtering in sequence, and finally combines the navigation results with the information of the laser rangefinder to calculate the road surface roughness information. The invention has high precision, high integration, anti-vibration and easy operation, and is used for road surface measurement of urban roads and expressways.
Description
Technical field
The present invention relates to a kind of vehicle-mounted road surface detection system based on Inertial Measurement Unit and laser range finder, the road surface that is applicable to urban road and highway is measured.
Background technology
Pavement of road flatness is the principal element that affects Road surface quality, is one of most important index of Pavement Condition, is one of leading indicator of inspection urban road and highway construction quality.
The domestic equipment for detection of this index mainly contains at present: 3m ruler, continous way smoothness measuring equipment, vehicular bump-integrator.This several equipment is widely used, but shortcoming is obvious.Wherein, 3m ruler measuring accuracy is low, detection efficiency is low and need bow while detecting bend over, workload is large; The instrument mechanical property of continous way smoothness measuring equipment is larger to the Accuracy of data, test speed for actual travel speed faster high-grade highway large area detect still restricted; The true section that vehicular bump-integrator time stability is poor, transformational is poor, can not provide road surface in recent years, along with to the improving constantly and the development of pavement management system (PMS) of highway service quality requirements, surface evenness fast, accurately method of testing just becomes one of problem of paying close attention to the most in road engineering.
Optical pavement checkout equipment is the mainstream development direction of current road surface measuring equipment, and this measuring equipment has fast, reliable, low, the easy enforcement of cost, automaticity advantages of higher.Domestic and international multiple producer has developed multiple Related product.In these products, majority has adopted the scanning of optical instrument road pavement, while adopting single accelerometer or dual acceleration meter to measurement, kinematic error compensation is carried out in the fluctuating of jolting of vehicle self, the shortcoming of this class checkout equipment is: pot life system is more on the one hand, as keep certain speed and can not have larger car body attitude to change while requiring vehicle to measure, measuring accuracy is poor on the other hand, in the situation that car body has obvious horizontal attitude to change, in the elevation movable information measuring, include large " vacation " movable information, increased system measurements error.
Summary of the invention
The problem that technology of the present invention solves is: overcome the deficiencies in the prior art, provide that a kind of precision is high, integrated level is high, anti-vibration, the vehicle-mounted road surface detection system based on Inertial Measurement Unit and laser range finder easy and simple to handle.
Technical solution of the present invention is: a kind of vehicle-mounted road surface detection system based on Inertial Measurement Unit and laser range finder, be made up of Inertial Measurement Unit, GPS module, PC104 computing machine, mileage gauge, laser pavement stadimeter and data acquisition board, Inertial Measurement Unit and GPS module are for measuring vehicle movable information; Laser pavement stadia surveying vehicle is to the distance on road surface; The operating range of mileage gauge measuring vehicle, and as the trigger pip of data acquisition board; Data acquisition board gathers angular velocity and the acceleration signal of Inertial Measurement Unit and laser range finder, sends to PC104 computing machine; PC104 computing machine receives signal, carries out successively Inertial Measurement Unit error compensation, navigation calculation and information fusion filtering, finally by the information fusion of navigation results and laser range finder, calculates surface evenness information.
Wherein said Inertial Measurement Unit is mainly by structure, three gyroscopes, three accelerometer compositions, wherein, three orthogonal installations of gyroscope, three orthogonal installations of accelerometer, the rotational angular velocity of three responsive Inertial Measurement Units of gyroscope, the acceleration of motion of three accelerometer sensitive Inertial Measurement Units.
Wherein said laser pavement stadimeter mainly comprises the multiple laser range finders that are placed in side by side on automobile preposition crossbeam.
Principle of the present invention is: by three gyroscopes and three accelerometer composition Inertial Measurement Units, utilize the motion angular velocity of three gyroscope survey car bodies, utilize the acceleration of motion of three accelerometer measures car bodies, utilize GPS to measure position and the speed of car body, capture card gathers three gyroscope information and three accelerometer information, PC104 receives the gyroscope information that capture card collects, accelerometer information and GPS receiver information, information is processed, in processing procedure, first utilize imu error model to carry out error compensation to gyroscope information and accelerometer information, recycling inertial navigation principle is carried out strapdown and is resolved the motion angular velocity and the acceleration of motion that obtain car body, then utilize Information Fusion to carry out combined filter to strapdown calculation result and GPS information, then calculate the position of car body by digital filtering method and smoothing algorithm, attitude information, finally by car body position, attitude information rises and falls as the road of motion compensation information and laser pavement stadia surveying and texture information merges, kinematic error in compensation laser pavement stadimeter measurement information, obtain surface evenness information according to international flatness IRI standard statistical routines statistics.
The present invention's advantage is compared with prior art: the present invention has adopted Inertial Measurement Unit to carry out motion measurement to vehicle, has improved the precision of motion compensation; Adopt GPS module and mileage gauge to revise motion measurement, overcome the Inertial Measurement Unit problem of dispersing of navigating; Finally build vehicle-mounted road surface detection system, realized the high precision road surface of changing fast and automatically and measured, greatly reduced the cost that road surface is measured, improved the precision that road surface is measured.
Brief description of the drawings
Fig. 1 is structure composition schematic diagram of the present invention;
Fig. 2 is the two isogonism axonometric drawings up and down of Inertial Measurement Unit structure of the present invention;
Fig. 3 is the front view of Inertial Measurement Unit structure of the present invention.
Embodiment
As shown in Figure 1, the present invention is mainly made up of Inertial Measurement Unit 1, GPS module 2, PC104 computing machine 3, mileage gauge 4, laser pavement stadimeter 5 and data acquisition board 6; Inertial Measurement Unit 1 is made up of structure, three gyroscopes 11, three accelerometers 12, three gyroscopes 11 adopt orthogonal mounting means, be used for the rotational angular velocity of responsive car body, three accelerometers 12 adopt orthogonal mounting means, be used for the acceleration of motion of responsive car body, data acquisition board 6 gathers angular velocity and the acceleration signal of three gyroscopes 11 and three accelerometers 12; GPS module 2 is for position and the speed of measuring vehicle, and metrical information is imported PC104 computing machine 3 into by usb signal line; Laser pavement stadimeter 5 is the distance to road surface for measuring vehicle, and data acquisition board 6 gathers the distance signal of laser pavement stadimeter 5 and imports PC104 computing machine 3 into; Mileage gauge 4 is for the operating range of measuring vehicle, and metrical information is imported the signal input of data acquisition board 6 into, and mileage gauge 4 is also for data acquisition board 6 provides trigger pip simultaneously; The distance signal that data acquisition board 6 gathers angular velocity, acceleration signal and the laser ranging module 51 of three gyroscopes 11, three accelerometers 12, imports PC104 computing machine 3 into; PC104 computing machine 3 receives the information of data acquisition board 6 and GPS module 2, be used for calculation function and the communication function of the system of bearing, the error compensation computing, the inertial navigation that carry out Inertial Measurement Unit 1 resolve and the computing of inertia/GPS information fusion filtering, finally, by the information fusion of inertia/GPS information fusion result and laser range finder, calculate surface evenness information.
When the present invention works, first start vehicle-mounted road surface detection system, carrying out system initial alignment and laser sensor demarcates, in aligning and calibration process, data acquisition board 6 gathers the distance signal of angular velocity, acceleration signal and the laser pavement stadimeter 5 of three gyroscopes 11, three accelerometers 12, signal is sent into PC104 computing machine 3 and carry out initial alignment computing and demarcate computing; Then vehicle enters and surveys district, system starts to measure, in measuring process, the distance signal of angular velocity, acceleration signal and the laser pavement stadimeter 5 of three gyroscopes of data acquisition board 6 Real-time Collection 11, three accelerometers 12, send into PC104 computing machine 3 and carry out strapdown and resolve and information fusion computing, stablized, navigation information accurately, the displacement information that navigation information and laser measurement are obtained merges, extract effective information by filtering, calculate surface evenness index.
As shown in Figure 2 and Figure 3, the structure of Inertial Measurement Unit is " Back Word type ", in structure, three gyroscopes 11 are installed on respectively on structure madial wall, structure lateral wall, structure bottom surface, three accelerometers 12 are installed on respectively on structure madial wall, structure bottom surface, PC104 computing machine 3 is installed on structure madial wall, and data acquisition board 6 is installed on structure lateral wall; The bottom surface of structure base and four sides are jointly as the reference for installation of whole fiber-optic inertial measuring unit, and the face that gyroscope and accelerometer are installed is simultaneously also the reference field of fiber-optic inertial measuring unit.
The content not being described in detail in instructions of the present invention belongs to the known prior art of professional and technical personnel in the field.
Claims (1)
1. the vehicle-mounted road surface detection system based on Inertial Measurement Unit and laser range finder, is characterized in that: be mainly made up of Inertial Measurement Unit (1), GPS module (2), PC104 computing machine (3), mileage gauge (4), laser pavement stadimeter (5) and data acquisition board (6), Inertial Measurement Unit (1) is connected with data acquisition board (6), formed by structure, three gyroscopes (11), three accelerometers (12), for angular velocity and the acceleration of measuring vehicle, this angular velocity and acceleration information are gathered by data acquisition board (6), GPS module (2) is for position and the speed of measuring vehicle, and this positional information and velocity information are gathered by PC104 computing machine (3), laser pavement stadimeter (5) mainly comprises the multiple laser range finders that are placed in side by side on automobile preposition crossbeam, the distance for measuring vehicle to road surface, and this range information is gathered by data acquisition board (6), mileage gauge (4) is for the operating range of measuring vehicle, and this operating range information is gathered by data acquisition board (6), and mileage gauge (4) provides trigger pip for data acquisition board (6) simultaneously, data acquisition board (6) gathers angular velocity and the acceleration signal of three gyroscopes (11) and three accelerometers (12), and it is sent institute's Information Monitoring into PC104 computing machine (3) and processes, the angular velocity of PC104 computing machine (3) to data acquisition board (6) and positional information and the velocity information of acceleration information and GPS module (2) are carried out error compensation, inertial navigation resolves and inertia/GPS information fusion filtering, finally the information fusion of inertia/GPS information fusion result and laser range finder is resolved, obtain surface evenness information, described mileage gauge (4) produces with rotation of wheel the pulse signal that frequency is directly proportional to travel speed, trigger data acquisition plate gathers three gyroscopes (11) of current time and angular velocity and the acceleration signal of three accelerometers (12), simultaneously for the time unifying between system component provides time reference, the structure of described Inertial Measurement Unit (1) is " Back Word type ", in structure, three gyroscopes (11) are installed on respectively on structure madial wall, lateral wall and bottom surface, three accelerometers (12) are installed on respectively on structure madial wall, structure bottom surface, PC104 computing machine (3) is installed on structure madial wall, and data acquisition board (6) is installed on structure lateral wall, the bottom surface of structure base and four sides are jointly as the reference for installation of whole fiber-optic inertial measuring unit, in addition, the face that gyroscope and accelerometer are installed is also the reference field of fiber-optic inertial measuring unit, three gyroscopes (11) adopt orthogonal mounting means, be used for the rotational angular velocity of responsive car body, three accelerometers (12) adopt orthogonal mounting means, be used for the acceleration of motion of responsive car body, while adopting described vehicle-mounted road surface detection system to carry out work, first start vehicle-mounted road surface detection system, carrying out system initial alignment and laser sensor demarcates, in aligning and calibration process, data acquisition board (6) gathers three gyroscopes (11), the angular velocity of three accelerometers (12), the distance signal of acceleration signal and laser pavement stadimeter (5), signal is sent into PC104 computing machine (3) to carry out initial alignment computing and demarcates computing, then vehicle enters and surveys district, system starts to measure, in measuring process, the distance signal of angular velocity, acceleration signal and the laser pavement stadimeter (5) of data acquisition board (6) three gyroscopes of Real-time Collection (11), three accelerometers (12), sending into PC104 computing machine (3) carries out strapdown and resolves and information fusion computing, stablized, navigation information accurately, the displacement information that navigation information and laser measurement are obtained merges, extract effective information by filtering, calculate surface evenness index.
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Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3399656B2 (en) * | 1994-09-14 | 2003-04-21 | 松下電器産業株式会社 | Pavement patrol device |
| JP3794988B2 (en) * | 2002-06-26 | 2006-07-12 | 三菱重工業株式会社 | Surface shape analysis method |
| CN2861966Y (en) * | 2006-01-20 | 2007-01-24 | 北京市中科盈恒科技有限公司 | Lazar inertial reference type fast road cross-section tester |
| CN101349564B (en) * | 2008-06-13 | 2010-12-08 | 北京航空航天大学 | An inertial measurement device |
| CN101825444B (en) * | 2010-04-09 | 2012-07-04 | 上海辉格科技发展有限公司 | Vehicle-mounted road spectrum testing system based on surface structured light |
| CN101914889A (en) * | 2010-08-10 | 2010-12-15 | 武汉武大卓越科技有限责任公司 | Laser evenness measuring system and method based on acceleration compensation |
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